As telecommunications equipment and networks become more readily available, there is increased usage among subscribers, of these devices and services. This is especially true in the world-market business scene, which continues to expand along with the technology. More people, it would seem, are communicating with each other more often, and in more ways. Consider the introduction of nationwide paging services, mobile cellular phones, personal portable cellular phones, pay cellular phones, interconnect trunking radio systems, fax machines and the multitude of simpler cordless telephones. As these various communications devices are used, care must be taken to keep track of the correlation between who is being called and that individual's phone number (or any unique access number associated with a person or machine). Even if one person, or machine, could always be associated with a single access number, the list of frequently called numbers would be far too great to be retained in human memory. Humans simply can't remember their favorite 20-100 frequently called phone numbers.
To assist the forgetful human, many of these telecommunications devices (e.g., phones) have a built in memory and speed-dial function. Maintaining the same list, however, in each of these devices is inconvenient, if not impossible. For example, a single person may have a work phone, a home phone, a cordless phone, a mobile phone, a portable cellular phone and a trunked radio (i.e., having interconnect capabilities), each having varied memory capacities and entry formats. As frequently happens in the life of a busy person, a new, frequently called number surfaces which then must be programmed into each of the aforementioned telecommunications devices. Not only is such a task inconvenient due to inconsistencies between entry formats, but even worse, is subject to errors during entry. Some of these devices store by numbers alone, some by alpha names and numbers, and some by spoken names. Furthermore, the addition of the memory system (particularly the storage/retrieval hardware required to access that memory) adds extra, and often substantial, cost to these devices. The problem is one of redundant entry and storage of common numbers in each phone device "database". If one wishes to make a call (e.g., on the public switched telephone network, or PSTN), and only has access through a foreign phone device such as a pay phone, then the multitude of independent personal phone device databases are rendered useless.
One possible solution to the aforementioned problem is to carry the database with you (i.e., an electronic telephone directory). Such electronic directories are readily available, but tend to create additional problems in terms of ease of access and dialing (e.g., some display the number for the human to dial, while others have an acoustic DTMF dialer). Further, it is rarely convenient to carry on ones person one of these electronic telephone directories, as they tend to be rather bulky, depending on the amount and type of information that is being stored.
Accordingly, a dire need exists for a centrally located personal directory that one can use to speed-dial frequently called access numbers. Such capability should be provided from any access point in the global telephone system.